This invention relates to the use of an attachable sail rig with an optional integrated water foil and a rudder for conversion of a conventional boat such as a row boat, kayak, canoe, and power boat into a sailboat or to modify an existing sailboat. The state of the art designs for attachable sailing rig systems limits their use to only specific types of boats and have relatively little sail area for the recommend size of boat, thus lacking in performance and the power required for a planing hull to plane. Generally, the sail area limitation is due to the absence of strong attachment points or mast rig for properly supporting a larger sail rig, especially on inflatable boats. Existing designs also use outboard water foil(s) or lee boards with elaborate attachments to the mast structure which increase the complexity and reduce the versatility and strength, and are unable to cant.
An example of an attachable sail rig which is no longer on the market, has the least amount of complexity using a single forward or bow water foil can be found in SAIL magazine article in June 2005, on page 59. This rig has a C-shaped mast step by Scully Fin which holds the water foil in the front end and mast in the back end, which is also stayed with small lines near the base of the mast. This indirect attachment reduces the rigidity between the mast and water foil, and places the relative center of sail area further aft of the water foil. With the sail area further aft and a fully shaped water foil which is not easily stalled at low speeds, the rig is prone to lock in irons when pointed too far into the wind, especially with a standard rudder. The C-shaped mast step attachment does not utilize the existing bow towing ring/safety line and oar locks for the distribution of the mast loads onto the hull. This rig design, as well as others with more complexity such as those by Sailboats To Go with lee boards (found in SAIL magazine article in June 2005, on page 58 and 59), also limit the strength and rigidity needed to carry additional sail area in strong winds.
Another sail rig which is not detachable and permanently installed on large sailboats is the Swing Rig by Van De Stadt found in SAIL magazine article in December 2008, on page 49. Although, this sail rig can be jibed around the front of the sailboat as a single unit, un-stayed and unsupported above deck. The dissimilarities of this sail rig will be described in this invention, which include a fixed mast rig with support struts and canting ability. Another similar sail rig used in windsurfing is also tacked or jibed around the front of the mast as a single unit and only supported by the sailor, although, unlike most sail rigs the mast and sail can be canted or tilted independently of the hull with the sail's foot optimally close to the water. In strong winds the windsurfing sail rig is canted windward and aft ward, adding to the sail's drag, but the added lift reduces the net weight and water drag on the hull which increases the overall performance. It is one of the most efficient sail rigs because of it's versatility, but unlike other sail rigs the complexity in sail control for water starts, steering, tacking and proper weight distribution requires good physical agility and takes time to master.
Another similar but unrelated sailing configuration can be found in the use of a conventional asymmetrical spinnaker, which can also be setup to tack around the front of a boat's standing rigging or forestay. Although, the sail has a free floating lull and is not tacked around the mast as will be described in this invention.